1. Field of the Invention
The present invention relates to an imaging lens and an imaging apparatus. In particular, the present invention relates to an imaging lens appropriate for use in an in-vehicle camera, a camera for a mobile terminal, a surveillance camera, or the like using an imaging device, such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor). Further, the present invention relates to an imaging apparatus including the imaging lens.
2. Description of the Related Art
In recent years, the size of an imaging device, such as a CCD and a CMOS, became small, and the resolution of the imaging device became high. Consequently, the size of the body of imaging equipment including such an imaging device became small. Therefore, reduction in the size of an imaging lens to be mounted on the imaging equipment is also needed in addition to high optical performance of the imaging lens. Meanwhile, lenses mounted on an in-vehicle camera, a surveillance camera and the like need to be structurable at low cost and in small size, and to achieve a wide angle of view and high performance.
An imaging lens composed of a relatively small number of lenses, and which has been conventionally known in the aforementioned fields, is disclosed, for example, in U.S. Pat. No. 7,280,289 (Patent Document 1), Japanese Unexamined Patent Publication No. 2011-065132 (Patent Document 2), and Taiwanese Utility Model Registration No. 390459 (Patent Document 3). Patent Documents 1 through 3 disclose imaging lenses, each composed of four lens elements including an aspherical lens.